PSIG to Pressure Ratio on Compressor Map Conversion

Remember, this is Input Vs. Output. So 14.7 PSIA at the inlet will need to be the case. 5000 ft. above sealevel is roughly 12.4 PSIA. You will need to figure the math on the difference for exact P/R at higher elevations.

The INPUT of this calculator is required to be PSIG.

PSIG to Pressure Ratio on Compressor Map Conversion

Type a value in the PSIG field to convert the value to P/R:
1.00 P/R = Sea Level or 1 Bar Atmospheric (14.7 psia) which is not reflected in the output. 1.00 (1 times PSIA) P/R would roughly equal ~7.35 psig which is not seen as a reading in RPM on the Map usually. An example of a MAP is below.

Pressure Ratio: